• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.63-70
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• 2010

Novel influenza A (H1N1) is a newly emerged flu virus that was first detected in April 2009. Unlike the avian influenza (H5N1), this virus has been known to be able to spread from human to human directly. Although it is uncertain how severe this novel H1N1 virus will be in terms of human illness, the illness may be more widespread because most people will not have immunity to it. In this study, we compared the codon usage bias between the novel H1N1 influenza A viruses and other viruses such as H1N1 and H5N1 subtypes to investigate the genomic patterns of novel influenza A (H1N1). Totally, 1,675 nucleotide sequences of the hemagglutinin (HA) and neuraminidase (NA) genes of influenza A virus, including H1N1 and H5N1 subtypes occurring from 2004 to 2009, were used. As a result, we found that the novel H1N1 influenza A viruses showed the most close correlations with the swine-origin H1N1 subtypes than other H1N1 viruses, in the result from not only the analysis of nucleotide compositions, but also the phylogenetic analysis. Although the genetic sequences of novel H1N1 subtypes were not exactly the same as the other H1N1 subtypes, the HA and NA genes of novel H1N1s showed very similar codon usage patterns with other H1N1 subtypes, especially with the swine-origin H1N1 influenza A viruses. Our findings strongly suggested that those novel H1N1 viruses seemed to be originated from the swine-host H1N1 viruses in terms of the codon usage patterns.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.4
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• pp.145-152
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• 2009

Novel influenza A virus, subtype H1N1 of swine-lineage, has been transmitted rapidly to many regions of the world. Rapid detection of the virus is essential to instigate appropriate patient care and public health management and for disease surveillance. The aim of this study is to determine the prevalence of novel influenza A (H1N1) virus in Korea using reverse-transcription real time polymerase chain reaction (rRT-PCR). Novel H1N1 virus was detected in a total of 8,948 nasopharyngeal samples from patients with influenza-like illness throughout Korea from August to September 2009. RNA was extracted from $300{\mu}l$of sample using an RNA extraction kit (Zymo Research, CA, USA). In the present study, Genekam kit (Genekam, Duisburg, Germany) was used to detect novel H1N1 virus. Novel H1N1 virus was found in 1,130 samples from a total of 8,948 samples (12.6%). The highest frequency was found in 10- to 19-year-olds (M: 29.3% vs. F: 16.4%), followed by 20- to 29-year-olds (M: 17.9% vs. F: 15.4%), 40- to 49-year-olds (M: 6.5% vs. F: 8.1%), 50- to 59-year-olds (M: 6.0% vs. F: 5.5%), and 30- to 39-year-olds (M: 4.6% vs. F: 3.8%). The mean positive rate was higher in men than in women (M: 14.7% vs. F: 7.4%). Novel H1N1 virus showed the lowest prevalence in patients over 60 years old. The positive rate increased daily and showed a significant high peak in mid-September 2009. In 19 provinces of Korea, Cheonan (41.1%), Busan (37.3%), Gangneung (33.3%), Jinju (32.1%), Ulsan (24.6%), Deajeon (23.7%) areas showed high frequencies and other provinces were found less than 10% of novel H1N1 virus. Since reverse-transcription real time PCR assay is rapid, accurate, and convenient, it may assist public health laboratories in detecting novel H1N1 virus. Moreover, these data could be useful for the management of patients with influenza-like illness.

• Journal of Life Science
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• v.30 no.9
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• pp.749-762
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• 2020

Influenza A viruses are circulating in a variety of hosts, including humans, pigs, and poultry. Swine influenza virus is a zoonotic pathogen that can be readily transmitted to humans. The influenza viruses of the 2009 H1N1 pandemic were derived from swine influenza viruses, and it has been suggested that the 1957 H2N2 pandemic and the 1968 H3N2 pandemic both originated in pigs. Pigs are regarded as a mixing vessel in the creation of novel influenza viruses since they are readily infected with human and avian influenza viruses. We isolated three novel H1N2 influenza viruses from pigs showing respiratory symptoms on a Korean farm in 2019. These viruses were reassortants, containing PA and NP genes from those of the 2009 H1N1 influenza virus in addition to PB2, PB1, HA, NA, M, and NS genes from those of triple-reassortant swine H3N2 and classical swine H1N2 influenza viruses circulating in Korean pigs. Mice infected with the isolated H1N2 influenza virus lost up to 17% body weight and exhibited interstitial pneumonia involving infiltration of many inflammatory cells. Results suggest that close surveillance to detect emerging influenza viruses in pigs is necessary for the health of both pigs and humans.

• Tuberculosis and Respiratory Diseases
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• v.70 no.2
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• pp.155-159
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• 2011

Recently, a novel influenza A (H1N1) has been recognized as the cause of a worldwide respiratory infection outbreak. Although the symptoms of a novel influenza A (H1N1) are usually mild, the disease can cause severe illness and death. A complication of novel influenza A (H1N1) is pneumomediastinum, a rarely reported condition. We report a case of influenza A (H1N1) complicating pneumomediastinum with subcutaneous emphysema, which had initially presented with blood tinged sputum and chest pain. In addition, we demonstrate bronchoalveolar lavage in influenza A (H1N1).

• Korean Journal of Veterinary Service
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• v.45 no.1
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• pp.31-38
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• 2022

Swine influenza (SI) is an important respiratory disease in pigs and epidemic worldwide, which is caused by influenza A virus (IAV) belonging to the family of Orthomyxoviridae. As seen again in the 2009 swine-origin influenza A H1N1 pandemic, pigs are known to be susceptible to swine, avian, and human IAVs, and can serve as a 'mixing vessel' for the generation of novel IAV variants. To this end, the emergence of swine influenza viruses must be kept under close surveillance. Herein, we report the isolation and phylogenetic study of a swine IAV, A/swine/Korea/21810/2021 (sw21810, H3N2 subtype). BLASTN sequence analysis of 8 gene segments of the isolated virus revealed a high degree of nucleotide similarity (94.76 to 100%) to porcine strains circulating in Korea and the United States. Out of 8 genome segments, the HA gene was closely related to that of isolates from cluster I. Additionally, the NA gene of the isolate belonged to a Korean Swine H1N1 origin, and the PB2, PB1, NP and NS genes of the isolate were grouped into that of the Triple reassortant swine H3N2 origin virus. The PA and M genes of the isolate belonged to 2009 Pandemic H1N1 lineage. Human infection with mutants was most common through contact with infected pigs. Our results suggest the need for periodic close monitoring of this novel swine H3N2 influenza virus from a public health perspective.

• BMB Reports
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• v.45 no.11
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• pp.653-658
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• 2012

After the outbreak of the swine-origin influenza A H1N1 virus in April 2009, World Health Organization declared this novel H1N1 virus as the first pandemic influenza virus (2009 pH1N1) of the $21^{st}$ century. To elucidate the characteristics of 2009 pH1N1, the growth properties of A/Korea/01/09 (K/09) was analyzed in cells. Interestingly, the maximal titer of K/09 was higher than that of a seasonal H1N1 virus isolated in Korea 2008 (S/08) though the RNP complex of K/09 was less competent than that of S/08. In addition, the NS1 protein of K/09 was determined as a weak interferon antagonist as compared to that of S/08. Thus, in order to confine genetic determinants of K/09, activities of two major surface glycoproteins were analyzed. Interestingly, K/09 possesses highly reactive NA proteins and weak HA cell-binding avidity. These findings suggest that the surface glycoproteins might be a key factor in the features of 2009 pH1N1.

• Journal of Microbiology and Biotechnology
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• v.22 no.5
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• pp.699-707
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• 2012

Since the 2009 pandemic human H1N1 influenza A virus emerged in April 2009, novel reassortant strains have been identified throughout the world. This paper describes the detection and isolation of reassortant strains associated with human pandemic influenza H1N1 and swine influenza H1N2 (SIV) viruses in swine populations in South Korea. Two influenza H1N2 reassortants were detected, and subtyped by PCR. The strains were isolated using Madin-Darby canine kidney (MDCK) cells, and genetically characterized by phylogenetic analysis for genetic diversity. They consisted of human, avian, and swine virus genes that were originated from the 2009 pandemic H1N1 virus and a neuraminidase (NA) gene from H1N2 SIV previously isolated in North America. This identification of reassortment events in swine farms raises concern that reassortant strains may continuously circulate within swine populations, calling for the further study and surveillance of pandemic H1N1 among swine.

• Journal of the Korean Professional Engineers Association
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• v.42 no.6
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• pp.42-46
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• 2009

Every year influenza contributes to the death of 72 people in the South korea, 20,000 in the U.S. and perhaps millions worldwide. The swine fever so-called the noble flu A H1N1, a strain of the flu virus, which jumped species and burst into the human population in March and April of this year. The outbreak of 2009 novel H1N1 was the fourth in 100 years. Fortunately, it led to today's comparatively tame swine flu than the vicious 1918, which was original H1N1 pandemic flu virus, killed at least 40 million worldwide in an ongoing pandemic era. Although the 2009 H1N1 which is still in full swing, this global flu epidemic is already teaching scientists valuable lessons about pandemics. Evidence accumulated these days indicates that the 2009 H1N1 was not entirely new to all human immune systems. This article introduces only an outline for our better understanding the basic mechanisms of influenza and the vaccination about longstanding fears of that worst-case scenario engendered pandemic that are paying off today.

• Tuberculosis and Respiratory Diseases
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• v.69 no.3
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• pp.207-211
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• 2010

Novel influenza A (H1N1) virus is a common pathogen of febrile respiratory infection recently. Here, we report the case of a 63-year-old male patient who presented with 3 days' ongoing cough and fever. He was diagnosed with novel influenza A (H1N1) pneumonia by real-time reverse-transcriptase-polymerase-chain-reaction (rRT-PCR). During treatment for novel influenza A (H1N1), his symptoms and radiologic findings improved initially, but multiple lung nodules developed subsequently and found on chest x-ray (on the 5th hospital day). Mycobacterium abscessus was isolated repeatedly from sputum and bronchoalveolar lavage fluid. To our knowledge, this is the first reported case of Mycobacterium abscessus lung disease in a patient with H1N1 influenza pneumonia.

• The Journal of Internal Korean Medicine
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• v.30 no.3
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• pp.558-570
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• 2009

Background : Since March 2009, when the first patient of novel influenza A (H1N1) was reported, many deaths have occurred in North and Central America. The start of the 2009 influenza pandemic was declared by WHO Director-General Dr. Margaret Chan on 11 June 2009, and the level of influenza pandemic alert raised from phase 5 to phase 6. There was no vaccine yet developed, and many experts worried that the novel H1N1 virus could kill as many or more as did the influenza pandemic in 1918-1919. Objective : To evaluate the possibility of treatment for 2009 novel influenza A (H1N1) using herbal remedies and other non-conventional therapies. Methods : We researched the clinical studies for novel H1N1 influenza virus-related herbal medicine or non-conventional medicine treatment using internet search engines including PubMed and CNKI. In addition, we reviewed many reports and clinical practice guidelines (CPG) for influenza A (H1N1). Results : Two case series were selected after reviewing 701 papers, and two CPG published by the Chinese government and Jilin province identified. They reported that the clinical symptoms were no more significant than seasonal influenza, and the condition of patients more than 45 years old was milder than those less than 45 years old. There are no patients with gastric problems, and oseltamivir has been used at the same time in all patients. Conclusion : The efficacy and effectiveness of herbal medicine and other non-conventional treatments for the novel influenza A (H1N1) is questionable, and more studies are needed to draw a firm conclusion. However, in the severe acute respiratory syndrome (SARS) experience in 2002/2003, it was demonstrated that herbal medicine can relieve all symptoms of SARS patients, promote absorption of lung inflammation, improve the degree of blood oxygen saturation, regulate immunological functions, reduce the required dosage of glucocorticoid and other medicines, and reduce case fatality rate. In light of the current situation that there is no vaccine or conventional treatment yet available, the study of herbal medicine and other non-conventional therapies are also necessary for appropriate evaluation.